[PATCH v4 09/10] PCI: ACPI: Bind GIC MSI frame to PCI host bridge

[Hanjun Guo]

From: Suravee Suthikulpanit <Suravee.Suthikulpanit at amd.com>

This patch introduces pci_host_bridge_acpi_msi_domain(), which queries
a GIC MSI irq-domain token and use it to retrieve an irq_domain with
DOMAIN_BUS_PCI_MSI bus type, and bind it to PCI host-bridge.

Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit at amd.com>
Signed-off-by: Hanjun Guo <hanjun.guo at linaro.org>
---
 drivers/pci/pci-acpi.c   | 18 ++++++++++++++++++
 drivers/pci/probe.c      |  3 +++
 include/linux/pci-acpi.h |  4 ++++
 3 files changed, 25 insertions(+)

diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
index 314a625..5f11653 100644
--- a/drivers/pci/pci-acpi.c
+++ b/drivers/pci/pci-acpi.c
@@ -9,6 +9,7 @@
 
 #include <linux/delay.h>
 #include <linux/init.h>
+#include <linux/irqdomain.h>
 #include <linux/pci.h>
 #include <linux/pci_hotplug.h>
 #include <linux/module.h>
@@ -16,6 +17,7 @@
 #include <linux/pci-acpi.h>
 #include <linux/pm_runtime.h>
 #include <linux/pm_qos.h>
+#include <acpi/acpi_gic.h>
 #include "pci.h"
 
 /*
@@ -681,6 +683,22 @@ static bool pci_acpi_bus_match(struct device *dev)
 	return dev_is_pci(dev);
 }
 
+#ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
+struct irq_domain *pci_host_bridge_acpi_msi_domain(struct pci_bus *bus)
+{
+	struct irq_domain *d = NULL;
+	void *token = acpi_gic_get_msi_token(&bus->dev);
+
+	if (token)
+		d = irq_find_matching_host(token, DOMAIN_BUS_PCI_MSI);
+
+	if (!d)
+		pr_debug("Fail to find domain for MSI\n");
+
+	return d;
+}
+#endif /*CONFIG_GENERIC_MSI_IRQ_DOMAIN*/
+
 static struct acpi_bus_type acpi_pci_bus = {
 	.name = "PCI",
 	.match = pci_acpi_bus_match,
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index a7afeac..8c1204c 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -12,6 +12,7 @@
 #include <linux/module.h>
 #include <linux/cpumask.h>
 #include <linux/pci-aspm.h>
+#include <linux/pci-acpi.h>
 #include <asm-generic/pci-bridge.h>
 #include "pci.h"
 
@@ -670,6 +671,8 @@ static struct irq_domain *pci_host_bridge_msi_domain(struct pci_bus *bus)
 	 * should be called from here.
 	 */
 	d = pci_host_bridge_of_msi_domain(bus);
+	if (!d)
+		d = pci_host_bridge_acpi_msi_domain(bus);
 
 	return d;
 }
diff --git a/include/linux/pci-acpi.h b/include/linux/pci-acpi.h
index a965efa..766d045 100644
--- a/include/linux/pci-acpi.h
+++ b/include/linux/pci-acpi.h
@@ -77,6 +77,8 @@ static inline void acpiphp_remove_slots(struct pci_bus *bus) { }
 static inline void acpiphp_check_host_bridge(struct acpi_device *adev) { }
 #endif
 
+struct irq_domain *pci_host_bridge_acpi_msi_domain(struct pci_bus *bus);
+
 extern const u8 pci_acpi_dsm_uuid[];
 #define DEVICE_LABEL_DSM	0x07
 #define RESET_DELAY_DSM		0x08
@@ -85,6 +87,8 @@ extern const u8 pci_acpi_dsm_uuid[];
 #else	/* CONFIG_ACPI */
 static inline void acpi_pci_add_bus(struct pci_bus *bus) { }
 static inline void acpi_pci_remove_bus(struct pci_bus *bus) { }
+static inline struct irq_domain *
+pci_host_bridge_acpi_msi_domain(struct pci_bus *bus) { return NULL; }
 #endif	/* CONFIG_ACPI */
 
 #ifdef CONFIG_ACPI_APEI
-- 
1.9.1